1. Field of the Invention
The present invention is generally related to the art of electrical connectors for electrically connecting with a flexible board such as a flexible printed circuit or a flexible flat cable.
2. Description of Related Art
U.S. Pat. No. 5,904,586 (named the ′586 patent for simplification) discloses a flexible board electrical connector, which comprises an insulated housing having an opening and a pair of projecting arms, a plurality of contacts having contact beams disposed in the opening and a pressing member attached to the housing for actuation between a closed position where it is close to the contacts and an open position where it is apart from the closed position. The contacts are made of substantially flat conductive sheet so as to provide pivot portions having arcuate tips with their axes extending in a direction of thickness of the conductive sheet. The pressing member has a plurality of compartments for accommodating the pivot portions, a pressing edge for depressing a flexible printed circuit against the contacts, and a bearing face engaging the pivot portions when the pressing member is turned downwardly to the closed position.
The ′586 patent discloses other embodiments of the pivot portions. Referring to FIG. 6 of the ′586 patent, the pivot portion is folded from the metal sheet in a U-shaped form, that is, the pivot portion is folded back from the upper beam of the contact. In the above embodiments, the pivot portions are received in the compartments each having a longitudinal wall and a later wall. When the pressing member is turned downwardly from the open position to the closed position, a flexible printed circuit is depressed to tightly contact with the contacts. The lateral walls of the pressing member engage with the pivot portions so as to prevent the pressing member from being deformed and coming off from the pivot portion. However, when the pressing member suffers from an unexpected force, the longitudinal walls of the pressing member urge the pivot portions biasing away from their correct position because of their shape. Accordingly, an electrical connection between the contacts and the flexible board is insufficient and unstable.
Referring to FIGS. 8–10, the pivot portions have apertures or studs and the pressing member has compartments for accommodating the pivot portions. Especially, as clearly described in the specification, each stud of the pivot portion may be made by a press machine or bonding a circular sheet. However, once the contacts suffer from an unexpected larger normal force, they would produce distortion and induce the studs to easily break off the contacts.